/*
* Add integers, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters.
*/
function safe_add(x: number, y: number) {
	const lsw = (x & 0xFFFF) + (y & 0xFFFF);
	const msw = (x >> 16) + (y >> 16) + (lsw >> 16);
	return (msw << 16) | (lsw & 0xFFFF);
}

/*
* Bitwise rotate a 32-bit number to the left.
*/
function bit_rol(num: number, cnt: number) {
	return (num << cnt) | (num >>> (32 - cnt));
}

/*
* These functions implement the four basic operations the algorithm uses.
*/
function md5_cmn(q: number, a: number, b: number, x: number, s: number, t: number) {
	return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}
function md5_ff(a: number, b: number, c: number, d: number, x: number, s: number, t: number) {
	return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a: number, b: number, c: number, d: number, x: number, s: number, t: number) {
	return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_hh(a: number, b: number, c: number, d: number, x: number, s: number, t: number) {
	return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a: number, b: number, c: number, d: number, x: number, s: number, t: number) {
	return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}

/*
* Calculate the MD5 of an array of little-endian words, and a bit length.
*/
function binl_md5(x: number[], len: number) {
	/* append padding */
	x[len >> 5] |= 0x80 << (len % 32);
	x[(((len + 64) >>> 9) << 4) + 14] = len;

	let i;
	let olda;
	let oldb;
	let oldc;
	let oldd;
	let a = 1732584193;
	let b = -271733879;
	let c = -1732584194;
	let d = 271733878;

	for (i = 0; i < x.length; i += 16) {
		olda = a;
		oldb = b;
		oldc = c;
		oldd = d;

		a = md5_ff(a, b, c, d, x[i], 7, -680876936);
		d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
		c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
		b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
		a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
		d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
		c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
		b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
		a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
		d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
		c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
		b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
		a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
		d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
		c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
		b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);

		a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
		d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
		c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
		b = md5_gg(b, c, d, a, x[i], 20, -373897302);
		a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
		d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
		c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
		b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
		a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
		d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
		c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
		b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
		a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
		d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
		c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
		b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);

		a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
		d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
		c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
		b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
		a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
		d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
		c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
		b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
		a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
		d = md5_hh(d, a, b, c, x[i], 11, -358537222);
		c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
		b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
		a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
		d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
		c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
		b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);

		a = md5_ii(a, b, c, d, x[i], 6, -198630844);
		d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
		c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
		b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
		a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
		d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
		c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
		b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
		a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
		d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
		c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
		b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
		a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
		d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
		c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
		b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);

		a = safe_add(a, olda);
		b = safe_add(b, oldb);
		c = safe_add(c, oldc);
		d = safe_add(d, oldd);
	}
	return [a, b, c, d];
}

/*
* Convert an array of little-endian words to a string
*/
function binl2rstr(input: number[]) {
	let i;
	let output = '';
	for (i = 0; i < input.length * 32; i += 8) {
		output += String.fromCharCode(((input[i >> 5] as any) >>> (i % 32)) & 0xFF);
	}
	return output;
}

/*
* Convert a raw string to an array of little-endian words
* Characters >255 have their high-byte silently ignored.
*/
function rstr2binl(input: string) {
	let i;
	const output: any = [];
	output[(input.length >> 2) - 1] = undefined;
	for (i = 0; i < output.length; i += 1) {
		output[i] = 0;
	}
	for (i = 0; i < input.length * 8; i += 8) {
		output[i >> 5] |= (input.charCodeAt(i / 8) & 0xFF) << (i % 32);
	}
	return output;
}

/*
* Calculate the MD5 of a raw string
*/
function rstr_md5(s: string) {
	return binl2rstr(binl_md5(rstr2binl(s), s.length * 8));
}

/*
* Calculate the HMAC-MD5, of a key and some data (raw strings)
*/
function rstr_hmac_md5(key: string, data: string) {
	let i;
	let bkey = rstr2binl(key);
	const ipad: any = [];
	const opad: any = [];
	let hash;
	ipad[15] = opad[15] = undefined;
	if (bkey.length > 16) {
		bkey = binl_md5(bkey, key.length * 8);
	}
	for (i = 0; i < 16; i += 1) {
		ipad[i] = bkey[i] ^ 0x36363636;
		opad[i] = bkey[i] ^ 0x5C5C5C5C;
	}
	hash = binl_md5(ipad.concat(rstr2binl(data)), 512 + data.length * 8);
	return binl2rstr(binl_md5(opad.concat(hash), 512 + 128));
}

/*
* Convert a raw string to a hex string
*/
function rstr2hex(input: string) {
	const hex_tab = '0123456789abcdef';
	let output = '';
	let x;
	let i;
	for (i = 0; i < input.length; i += 1) {
		x = input.charCodeAt(i);
		output += hex_tab.charAt((x >>> 4) & 0x0F) +
			hex_tab.charAt(x & 0x0F);
	}
	return output;
}

/*
* Encode a string as utf-8
*/
function str2rstr_utf8(input: string) {
	return decodeURI(encodeURIComponent(input));
}

/*
* Take string arguments and return either raw or hex encoded strings
*/
function raw_md5(s: string) {
	return rstr_md5(str2rstr_utf8(s));
}
function hex_md5(s: string) {
	return rstr2hex(raw_md5(s));
}
function raw_hmac_md5(k: string, d: string) {
	return rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d));
}
function hex_hmac_md5(k: string, d: string) {
	return rstr2hex(raw_hmac_md5(k, d));
}

export function md5(str: string, key?: string, raw?: any) {
	if (!key) {
		if (!raw) {
			return hex_md5(str);
		}
		return raw_md5(str);
	}
	if (!raw) {
		return hex_hmac_md5(key, str);
	}
	return raw_hmac_md5(key, str);
}
